After all, this game rarely has much respect for form and Lionel Messi is injured. "It's a great game for us at this moment because we have no choice but to stand up," Toni Kroos told AFP this week. "We have to show how good we are against a difficult opponent and I think we can do it." A surprise success would make sacking Lopetegui harder to justify but five games without a win, more than eight hours without a goal, these are not quickly forgotten either.

There were disgruntled whistles at full-time on Tuesday, the home fans deflated after watching a team that featured UEFA's best goalkeeper, defender and player hang on for a 2-1 victory over Viktoria Plzen.

After the match, Lopetegui talked about turning points and changing dynamics but his demeanour perhaps betrayed the truth. "I don't often smile anyway," he said. Madrid's chaotic performance had weakened his position, not strengthened it.

He instils confidence, which leads to creativity and precision. He also sets the rules and for some, perhaps Perez included, this team has been indulged for too long. For their part, the players might argue they have struggled before and come through, not least under Zinedine Zidane last season.

"The confidence, in my opinion, is not a problem," said Kroos, whose Germany coach Joachim Loew is among those considered a potential successor to Lopetegui. "We have many champions in the World Cup and the Champions League, and we have shown we can turn around tough situations. Remember that in the last few years, we have not only played good games, but there have also been bad ones too.

"We are creating, we are doing everything we can to get good results and that proves we are behind the coach. He is a very good coach in my opinion and I'm confident we can turn this around with him." Opposite Lopetegui this weekend will be Ernesto Valverde, watching his Barca side with their own superstar extracted too. This will be the first Clasico without Lionel Messi or Cristiano Ronaldo since December 2007. The strikers then included Ruud van Nistelrooy and Robinho for Madrid, Samuel Eto'o and Ronaldinho for Barcelona.

Messi will return, in three weeks if his right arm heals as expected, but Ronaldo's permanent absence has weighed heavier with every chance missed.

When Barca went three games without a win last month, the feeling was both clubs were in crisis. Lopetegui was under pressure, but so was Valverde. Then Messi blew away Tottenham at Wembley and, a day later, Madrid lost 1-0 to CSKA Moscow, lacking the snap and spark Ronaldo once provided and that Messi had given the night before.

He also knows failure to put away a wobbling rival will see the doubts circling again, but win, and a seven-point gap opens up. Or, Madrid can cut it to one, with only a single game, at home to Real Valladolid, against an opponent in the top half before Christmas. It will either be a chance for a Lopetegui revival or, the perfect start for his successor.